I have been lucky and only had to deal with three broken pieces at A&C shows. One was a drunk lady who dropped a teapot lid when flipping over the teapot. She stumble/ran away a cop saw it happen and brought her back she refused to pay anything and the cop asked I wanted a statement to take her to small claims court, I did not waste my time.
The next one was a lady who dropped a little pourer while picking up another piece. I was going to let it go but she wanted to get the only other little pourer I had ($90) she wandered in my booth for a while and chatted, she had a volunteer shirt on. While bagging up someone else the lady left. when packing down noticed the pourer gone, she stole it. She dropped the other one while trying to conceal it.
So the last one, which happened this year got my full fury. the piece was fragile and placed on a high shelf with a sign that could not be missed saying please ask for assistance. It looks like metal (she thought it was) and turned a handle that snapped off in her hand. The claimed it was broken when she picked it up, but I heard it break. Got her name and info and was telling her that if she didn't pay for the piece I would follow up in small claims court. She negotiated a price that was about wholesale and wrote me a check... If you guessed it was a bad check you win.
Not sure what I will do the next time but I at least want to get the interaction on video.